1. Field of the Invention
The present invention relates to an antenna device, a communication apparatus, and a method of manufacturing the antenna device.
2. Description of the Related Art
Magnetic coupling communication schemes typified by near field communication (NFC) are also adopted in portable information terminals such as smartphones or wearable terminals, and antennas are mounted to realize the functions. With lightness, compactness, and multi-functions of such portable information terminals, requests for miniaturizing and thinning antennas to be mounted have increased.
With miniaturization of antennas, loop antennas used in the related art are easily affected by peripheral metal. Therefore, communication distances may be shortened. On the other hand, since antennas with magnetic bodies wound by conductive wires are rarely affected by metal, it is known that communication distances increase.
In some cases, connectors are used to connect the antennas with such magnetic bodies wound by conductive wires to substrates (main substrates) on which microcomputers, NFC communication ICs, wireless power supply ICs, or the like are mounted. For example, cable relay connectors for improving workability of local area network (LAN) wires have been disclosed (see Japanese Unexamined Patent Application Publication No. 2006-269164 A).
However, a connector in Japanese Unexamined Patent Application Publication No. 2006-269164 A does not relay cables with different diameters to each other. That is, covered wires in which the diameters of lead wires of connectors are several hundreds of μm are generally used. When conductive wires which wind magnetic bodies used for antennas and have diameters of 10 μm to 100 μm are connected directly to connectors, the connectors may be moved and antenna characteristics may vary. When conductive wires used for antennas are connected to connectors, general connectors may not be used. Therefore, cost may increase. Further, when conductive wires which have thick diameters and can be connected to connectors are used, miniaturization and thinness required in smartphones, wearable terminals, or the like may not be achieved.
In view of the foregoing circumstances, there is a need to provide an antenna device, a communication apparatus, and a method of manufacturing the antenna device that realizes miniaturization and thinness and suppress variation in antenna characteristics when an antenna with a magnetic body wound with a conductive wire and a main substrate are connected by a connector.